


a transformation of current into body heat

by chii



Category: Voltron: Legendary Defender
Genre: Alien Biology, Alien Sex, Aliens, Bottom Shiro, Bottom Shiro (Voltron), Come Inflation, Come Swallowing, Come as Lube, Double Penetration, F/M, Light BDSM, Light Dom/sub, Multiple Orgasms, Shapeshifting, Spitroasting, Tentacle Sex, Tentacles
Language: English
Status: Completed
Published: 2017-03-09
Updated: 2017-03-09
Packaged: 2018-10-01 12:14:52
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 5,111
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10189694
Author URL: https://archiveofourown.org/users/chii/pseuds/chii
Summary: “I really don’t think that’s going to be an issue, Princess, ” Shiro says with all the certainty of someone who is really, really into the idea of his girlfriend being able to grow tentacles at will just because he asked for it. “But, noted.”





	

**Author's Note:**

  * For [neomeruru](https://archiveofourown.org/users/neomeruru/gifts).



> Last night I asked people to give me drabble suggestions. Linds brought up the tentacle porn we'd talked about months ago, and I foolishly thought, sure, yeah, tentacle porn will be like 1k max.
> 
> H-hah. Song title shamelessly stolen from the lyrics of Dance Electric, mostly because I know I can't name this "Shiro gets banged by Allura's alien tentacles and is really into it."

Shiro hits the ground with a wheeze that shifts into a laugh, tapping the mat three times to signal that he’s done, he’s out, she’s won. It’s not a surprise; five out of ten times she’ll beat him when they spar, but it’s better than the nine out of ten it used to be when they first started. Thousands of years of experience means he’s got some catching up to do, but it isn’t like he doesn’t enjoy this. (This, being her throwing him halfway across the room like he weighs nothing. He’s pretty sure she’s into it, too.) 

To her credit, she doesn’t ask if he’s alright, or look worried when she slams him against the mat. Instead, Allura’s smug once she’s given him the cursory once-over and ensured the bruises blooming on his skin are ones that don’t look too serious. Rather than rise up and slide off of him, though, she crosses her arms over his chest and settles in over him. Straddling his waist comfortably, she tilts her head down until the tips of their noses touch and she can steal a quick kiss. 

“I want,” Allura begins with all the causal consideration of someone building up to requesting something the other person might object to, “you to tell me what had you so...flustered, last time we spoke about changes I could adopt for when we are...intimate.” 

It’s cheating, Shiro wants to protest, but that’s really not. The rules state whoever wins the betting bout of sparring gets to ask for anything they want - information, a favor, whatever the case may be so long as it doesn’t hit against any of the limits they defined earlier. That she’s using it to pry information out of him - information about his preferences regarding sex - isn’t a _surprise_ but it does get him to narrow his eyes at her and wrinkle his nose. Since she wins so often, she doesn’t tend to ask for more than kisses as favors.

“It is not _cheating_ ,” Allura says primly before he can argue the point just for the sake of arguing. It’s not, he lost fair and square, and he’d be lying if he said it wasn’t something that he’d considered asking about a few times. 

“Let’s shower, eat, and then we’ll see,” he compromises and that’s that.

\---

Thankfully, he doesn’t have to go to Pidge to borrow any paper; Allura looks particularly smug as she passes over the tablet she keeps by her bedside, the drawing function open. Generally, it’s used to bridge the divide between languages when the translator doesn’t quite pick things up. Right now, it feels a little ridiculous to take the pen and starts sketching while Allura starts unclasping her cape and working off her dress too slowly for it to be anything other than intentionally distracting.

Thing is, Shiro’s never been an artist. He can sketch and doodle, and it’s gotten him through some of the more boring classes at the Garrison, sure. He’s far, far better at technical diagrams, though, all the straight lines and planes and careful, detailed measurements. When it’s done, he grimaces a little, but at least it’s pretty clear exactly what he’s talking about. Truthfully, he thinks it looks more like an extremely weird looking plant than anything particularly useful, but then Allura’s naked and prowling up the end of the bed toward him and he figures that when you’re sleeping with a shape-shifting alien who’s willing to accommodate basically anything you want, lackluster art skills can be forgiven.

“Hm,” Allura says once she looks at it, like she’s not a long line of bare skin against his side, like her hand isn’t pressed against the waistband of his sweats, fingers dipping under to drag over skin. “Oh, is that all? Like a Carzyian.” 

He doesn’t have the faintest idea of what a Carzyian looks like, but she...doesn’t seem bothered or even remotely phased, so Shiro rolls with it. “You know it’s not-- this isn’t because I don’t find you attractive. It’s not that at all.” 

It seems unnecessary to say it, but Shiro wants to all the same; he loves her just how she is, for who and what she is. That she can and has shifted forms a few times during sex is an added bonus, but not something required or expected. What _is_ expected, is the way her smile softens and she settles the tablet to the side of the bed, sliding one long leg over the narrow line of his waist to straddle him. 

“I am _well_ aware of how attractive you find me like this,” Allura purrs, her fingers skimming from her knees, up the insides of her thighs, the swell of her hips, her belly, and up to cup her breasts. By the time his eyes make their way up to her face, she’s watching him with that pleased, borderline smug look and he can’t find it in himself to be shy or regret how obvious his appreciation of her is. “Let’s see if I understand this correctly.”

\---

Carzyians, as it turns out, are twelve feet tall and have hands the size of a dinner plate, though no fingers in the technical sense. It takes a little tweaking -- while he’s not opposed to tentacles coming out of her arms, it’s a little unnecessary, given everything else.

It starts with Allura perched over him. She holds a hand over his eyes while she shifts, kissing and rolling her hips against the line of his cock trapped under his sweatpants until there’s a wet spot visible against the thin material. It continues with him breathless and shivering against the bed as she uses every single thing she’s learned about his body to work him up while shifting. Some part of him wishes he could watch, but that’s one of the rules they’ve agreed upon at her request, and he hasn’t asked about how or why that’s one of her limits. It’s enough that it is. 

“There, I think,” Allura says finally, after what feels like ages. Nothing...really feels different except for her weight on his hips - heavier, maybe. Shiro still can’t see what’s changed but by this point he’s also worked up enough to the point that he hasn’t really been paying attention to anything _but_ what she’s done to him. “If this is...not as appealing as anticipated, I will not be offended.” 

“I _really_ don’t think that’s going to be an issue, Princess,” Shiro says with all the certainty of someone who is really, really into the idea of his girlfriend being able to grow tentacles at will. His tongue slides along his kiss-swollen bottom lip. “But, noted.” 

When her hand is removed, it takes his eyes a moment to adjust and then another moment to fully register everything he’s seeing which is - a lot. He’s not entirely certain how many tentacles there are because they’re moving independent of each other, various thickness and length. For a moment, a half dozen questions go through his mind - how many could she feasibly do? How does the shapeshifting work, if the parts she’s ‘creating’ end up technically being more body than she starts with? Where does all of the extra matter _go_ , when she changes back to herself?

“Oh,” Allura sighs, and the faux-disappointment in her voice is enough to jerk his attention up from the tangle of tentacles that are creeping their way up under his already rucked-up shirt with intent. “I thought I had distracted you enough while changing, but evidently not. Save your questions for after, I have plans for you, my paladin.” 

There’s a threat laced behind those words and when she bends down to kiss him again and he feels the slow, steady crawl of tentacles up under the material of his shirt, the idea of that threat is enticing more than anything else.

\---

“Carzyians do not normally have self-lubricating appendages. Given the circumstances, however, it seemed...more efficient.”

The circumstances, as she’s calling them, are Shiro on his hands and knees, trembling and groaning his way through a second orgasm, three of her smaller tentacles curled inside him, twisted together, the tips blunted rather than the soft, rounded edges she’d used to open him up. 

He couldn’t self-lubricate like Alteans could, something she had lamented at the start. It was almost a shame if it weren’t for the fact that it meant she could slick her fingers and finger him open until he was panting into the pillows and practically gagging for it. On the seemingly endless list of things Allura enjoyed doing to and for him, this was one of her favorite activities, he was sure of it, if only because of how often she took advantage of getting him to a state of near incoherence with fingers alone before proceeding. 

“Head up,” Allura murmurs gently, but there’s steel behind the words, an order that he doesn’t want to resist. Slowly, he raises his head from where it’d been hanging, mouth open and wet as he pants. Inside of him, the tentacles shift, pulling out slowly, until the bundled tip rests against the slick mess of his hole and lingers there, stroking. Her hand slides up from where she’d let it curl into a loose hand for him to fuck into; mostly, the sheets underneath them took the majority of his orgasm but there’s a streak of white across her knuckles and her fingertips are slick with his spend. “Clean up the mess you made.” 

He’s not quite sure how she manages to maneuver to the point where she’s holding her hand in front of him to lick clean while the nest of tentacles writhes against his hips and the curve of his ass, but he’s also far past the point of caring. Shiro’s mouth opens obediently and she feeds him two fingers. He licks them clean and then chases after them for the rest, pressing a lingering kiss to her wrist when it’s done and he’s able to catch his breath. 

“Thank you, Princess,” Shiro mumbles, the words a low slur against her skin, pressing another kiss there. It’s a check in and a break in equal parts and he hears her low laugh of approval, of pleasure. Uttering anything more complicated is far past the point of what he can manage and distantly, he’s grateful she doesn’t push for anything further. Instead, there’s a moment of disorientation where suddenly the bed’s no longer under his hands and knees and there are tentacles curling firmly around him, velvet-soft but strong enough to lift the weight of him and turn him over. 

A few moments ago he would have said that he couldn’t go again any time in the immediate future but inevitably, any time she lifts him like he weighs nothing and maneuvers him to where she wants him there’s an answering tug of heat from his belly that makes him think _maybe_. Allura settles him on his back, legs splayed on either side of her, just to the right of the wet spot on the bed. The consideration of it makes him smile through the haze, sinking back into the sheets and pillows with an ease that only comes during times like this when all he has to do is lie back and take what she gives him, trusting her to handle things. To decide what he’s capable of taking and giving her. 

“Look at you,” Allura murmurs and he’s distantly aware of the way her hand cups his cheek, a little damp, a little sticky after he’d cleaned it off but it barely registers as anything worth noting given all of the other fluids sex involves. Against his thigh, his cock is just barely softening but hyper-sensitive, a side-effect of the tiny, flavorless vial he takes when they want his stamina to match that of an Altean. A few more moments is all he needs to be ready again without the edge of over-sensitivity, which is exactly why she knees his legs further apart and the bundled, thick tip of tentacles nudges under his balls and dips down to his entrance again, pushing in achingly slow. 

Distantly, he’s aware of the whine that he can’t swallow down, his hands flattening against the blankets, palms pushing into the mattress, fingers curling into the sheets as it keeps going and going and going, achingly slow. It’d felt deep when she was fucking into him before while he was on his hands and knees, but now, somehow it feels even more overwhelming. 

“Allura,” Shiro begs before he can catch himself and groans when she stills, his eyes slitting open. It takes two blinks before the image of her over him (hair twisted into a loose knot, cheeks flushed, teeth flashing in a smile that’s dangerous with intent) then it solidifies and he tries again, desperate. “ _Princess_.” 

It’s too late for the correction; he can read it in the way she holds herself, markings glowing, eyes focused and sharp on him. It wasn’t a safeword and he’s not safewording or signaling out now, a little thrill running through him as he wonders just what it is she’s going to do to correct his misstep. 

“There are only two rules, Shiro,” Allura reminds softly, no disappointment to her tone because there doesn’t need to be. Like this, he’s aching to please her, to do exactly what she expects of him, from him and the only recourse left is for her to make it right in whatever way she chooses for him, from him. He trusts her to determine what’s necessary. Inside, there’s the terribly strange sensation of the tentacles twisting, writhing against each other from where they’d been curled; it’s nothing at all like when she works him open with her tongue and fingers. It’s sharper, more intense after the two orgasms and his whole body jerks when they press just right, too lingering to be anything other than intentional. The fact that she does it again just for the whole-body jerk and shudder it gets her is only more proof of intention. 

“ _Princess-_ ” It’s almost a plea at this point and he’s rewarded with her hand curling against his cheek as tentacles wind around his ankles and he’s bent neatly in half, knees to his shoulders. The insides of his thighs burn with the faint strain of it and his hands fist tighter in the covers, ripping top sheet up from the mattress with a soft pop and release as it skitters across the bed toward them. Neither of them pay any attention to it; Shiro’s too focused on the press of something else against him, thicker and slick like she’s taken to covering it with lube even if he knows that’s not true. She hasn’t reached into any drawers, unless he’s entirely missed it with how distracted he is.

Over the bed, another set of tentacles crawls up but they don’t wind around his wrists like they did his ankles. They’re a light pressure over where his hands rest - enough that it takes a touch to strain against them and escape, but not so much that his hands are held down. Even through the haze of arousal and stimulation he recognizes what she’s doing and shivers in response, squirming. 

“Tomorrow, you are going to ask me questions about the Carzyians,” Allura says with certainty. Right now, they both know he’s not going to retain anything but the basest of orders and bits of information she tells him, so she’s correct about the whole _tomorrow_ thing. “They reproduce similarly to humans, none of the eggs you indicated. Open again.” 

“Nnhg,” Shiro responds eloquently, parting his lips when her fingers stroke over the bottom one. Given how good everything is already, it’s not like he’s _disappointed_ exactly. This is already leaps and bounds above what he expected to get when they’d discussed just what she could shift and change with her abilities. The fact that Carzyians don’t have ovipositors like Alteans isn’t heartbreaking when there’s _everything else_. 

“Wider,” Allura commands gently, but it’s not her fingers that slide into his mouth when he parts his lips. Instead, one of the tentacles pushes wetly against his mouth, slides _into it_ and fills him, resting hot and damp on his tongue. It doesn’t taste like much - faintly like skin, the slick it gives off a little salty but otherwise not objectionable. He has no idea if these tentacles work like her normal genitalia - if she can orgasm if he simulates all or some of these or not. She’d seemed to enjoy fucking him with them earlier, but he wasn’t certain how much of that was simply because _he_ enjoyed it and how much was pleasure she gained from sensation. His tongue dragging over the soft underside of the tentacle gets a shiver and a hitched breath, which seems to answer the question, though. 

One of the tentacles slips slickly over the inside of his thigh and curls around his cock, starting at the base, wrapping in tight, neat circles until from his balls to the flared head of his dick is surrounded and the tip presses wet against his own, not unlike a tongue as it drags over. Between the slick from the tentacle it feels almost a like a tongue dragging over the over-sensitive head, wringing another choked groan out of him. He squirms, but there’s nowhere to go, nothing to do but just take whatever she deigns to give or take from him. 

“Eyes on me,” Allura murmurs. There’s no doubt in his mind this isn’t a request, despite the soft purr to her words and the way she’s smiling down at him. The tentacle that had nudged at his entrance earlier pushes again, firmer this time and it’s only when it keeps _going_ that he realizes how much thicker it is than the others; closer to Allura’s own size. 

“Hhnh--” Speaking is impossible with the heavy weight of her in his mouth; he tries, a strangled groan and muffled attempt at a word interrupted by the steady press of the tentacle deeper and then it drags out until it smears over his lips and he’s left chasing after it. 

Allura still hasn’t punished him for his mistake, though, which puts him on edge; there’s no chance that she’s forgotten. It’s more likely that she’s weighing the proper time to do it and the extra edge of anticipation makes everything sharper, hotter. Every time Shiro’s eyes slide shut he forces himself to open them again, to watch her above him, hips moving in lazy pushes that match with the slick slide of the tentacle between his thigh and the one in his mouth, pushing just shy of where he might consider too much, riding the line perfectly. Around his cock, the steady ripple of what’s wrapped around him coupled with the wet slide over the head is enough to drag choked, needy noises out of him around the weight in his mouth. 

It’s only when orgasm starts to build again, each steady, deliberate push of the tentacle between his thighs _just enough_ to send pleasure skittering down his spine, that he realizes where she’s going with this. 

The tentacle around his cock starts to tighten when his noises get higher, more choked around the one in his mouth. A mix of spit and slick slides from the corner of his lips, down his cheek and his lashes are damp when he forces his eyes open again, hands flexing helplessly into the covers. 

She’s not going to let him come; the realization hits him when he starts trying to push up into the tentacle or down against the other one and all she does is lean over him and keep fucking while the one around him tightens pushes down around the base of him. Better, maybe worse still - she’s going to make him ache for it. Two of the thinner tentacles trail up his sides and drag over his nipples and it’s like they’re two points that lead straight to his dick, sensation lighting up his spine leaving him quivering where he’s pinned.

“Please,” he tries around the thickness in his mouth, the word an unsteady slur, barely understandable around the wet noises the tentacle makes with each push in and out, just shy of choking.

“You can wait, can’t you, darling.” Another non-question, this time coupled with the English version of the pet name instead of the Altean one she normally switches to that the translators pick up. Her face swims in and out of sight between long blinks, desperately trying to be good, trying to obey her order to keep his eyes on her but it’s next to impossible when everything crushes together, stimulation overwhelming. “I know, I ask much of you but I never ask more than what you’re able to give and you are so, so good for me.”

Distantly, he recognizes that there’s praise there despite his earlier failing, that there are words he should care about but they slide in one ear and his brain can’t seem to make sense of them right now, not when confronted with everything else. Words don’t matter anyway, not when he realizes that with each subsequent thrust between his thighs and between his lips, the tentacle seems -- larger. Wider. He’s not certain of it at first, chalking it up to over-stimulation, too much, too soon and there’s nowhere for him to escape from it so he’s left to _take it_ , but when the tentacle between his thighs slides out and there’s a moment of tension before it slithers back in, he jerks, tenses. 

“Similar to humans, but not entirely so,” Allura murmurs above him, and a hand slides down to wipe where tears slid from the corners of his eyes as she stops him from another orgasm, removing any stimulation from where he needs it to push him over the edge. “A….mm, a compromise between your request and what you enjoy when I am entirely Altean.” 

The meaning isn’t clear until the next drag out takes effort and feels larger once more when it slides home. The one in his mouth is similar and there’s the faintest edge of salt to the taste of her when she drags out and smears the tip of it over his lips, makes him work for it to swallow it down again. Between trying to figure out what she means and the urge to try and fuck himself down onto something, anything to chase the orgasm she denied him, all he can manage is a choked groan and arch of his back.

“Almost,” Allura murmurs, shifting closer, the sheets rustling when she pushes herself up against him, the tops of her thighs bracing the bottom of Shiro’s while the nest of tentacles slides over him, the insides of his thighs, the trembling line of his belly. 

Shiro’s fine -- he’s fine and he’s got all of this under control, he can withstand anything, he thinks, all the way up until he forces his eyes open again and sees the way she’s looking at him. Raw desire and terrible fondness and despite the fact that thinking anything above base needs is like trying to wade through molasses, he responds to it. His hands strain against the tentacles holding them to the bed, aching to touch her, but he’s denied this, too. His thighs go tight with tension, toes curled, calves tense as he trembles helplessly on the bed and watches her face as she buries herself as deep in him as she dares to go and then presses a hand to his belly. 

A moment later, it becomes clear why; it wasn’t an egg like it was with her ovipositor when they did this. There’s the wet-hot release normally associated with it when she comes, but it’s so much _more_. She presses as deep as she dares in his mouth, just shy of choking him and spills down his throat with a rush that he fights and struggles to swallow, jerking helplessly against the sheets while the tentacle between his thighs pushes in, swells and locks. 

It’s too much; it seeps from the corners of his lips, slides out around the fat bulge of her tentacle between his thighs and the hand on his stomach just to watch the way it distends slightly is equal parts claiming and admiring. Allura’s fingertips stroke over the soft swell, almost like she can feel herself in him. Maybe she could; he doesn’t have the faintest idea. All he knows is that she’s gorgeous above him, flushed and trembling as she rides out her orgasm, regal even in this, in control even in a terribly vulnerable moment. 

Under normal circumstances, that would have been enough to coax him over the edge, coming all over himself. Instead, the tentacle wrapped tight around the heavy weight of his balls and his cock prevents him from doing anything, keeps him riding the razor-thin edge, trembling against damp sheets. He can’t beg for her to let him come -- he _won’t_ , and it’s not enough to get him to safeword out so instead he trembles and bears it. 

One swallow, and then another, his tongue dragging against anything while he clenches down around her and squirms, choking on another groan when he feels how full he is, the knotting sensation from earlier making sense. Against the bed, his hands twitch again, palms pushed into the bed, fingers lifting up and then flexing helplessly as he tries to prove he’s been good, he’s obeying. 

“Hold on,” Allura breathes, her voice lower, rougher-post orgasm. The tentacle in his mouth slips out with a wet noise that makes him shiver all over again, the last few pulses of come spilling over his lips, his nose, down his throat. He licks clean what he can and sucks in a wet breath, panting now that he’s able to take full breaths again. Between his thighs, the tentacle pushes deeper once and then a second time like she’s fucking the come further into him to claim him. Then, it slowly eases out until it pops free and the gush of liquid between his thighs is enough to rip another noise out of him, shocked. 

“‘Ve been good, Princess, please.” Eyes open, on her, _beg_. He repeats the instructions to himself, six words about all he can manage to keep in the scrambled mess of his head when he’s like this. Slowly, the tentacle around his cock starts to unwind. First the bit touching the flushed, angry red tip. Then, round by round, the rest of it circling him. It’s never enough to bring him over despite how sensitive he is and by the halfway point he’s making incoherent, desperate noises that are almost words, begging her to let him come. Both hands lift what scant amount they’re allowed, fingers raising toward her. “Princess, _Princess_.” 

“Almost,” Allura assures but the steady, slow unwinding continues until his cock presses wet to the trembling line of his stomach. Between his thighs, another tentacle skims through the hot mess of come that’s spilled out of him and slides back in easily given how wet it is and how much smaller it is than what was there before. Even that faint touch is enough to rip a strangled whine out of him as he fights between rocking back and edging away from it, shifting restlessly on the bed.

Finally -- _finally_ her hand slides down and covers the line of his cock and curls around it. She doesn’t need to stroke, doesn’t need to do anything more than touch him before his cock twitches and the fire she’s been stoking for the last God knows how long flares white-hot in his belly. He’s not sure if he makes any noise during it, blanking out as he jerks his hips up into her hand, eyes rolling back in his head as he rides it out, shuddering against her. 

There’s lost time between post-orgasm and getting tucked into bed. Distantly, he’s aware of the tentacles from earlier vanishing, the light weight against his arms leaving, the press of her hand against the curve of his knee so there’s always a point of contact while he pants helplessly into the damp pillow. When her hand slides over him again and it’s cool and damp he manages to slit his eyes open and give her a sleepy smile, exhaling slowly. She cleans him up as best as she can and he does what he’s able to try and shift, accommodating her but for the most part he lies there and tries to breathe. 

Once she’s done, crawling over the bed to settle at his side again, he manages to lift his human hand up and settle it over the curve of her hip, still floating, words difficult to reach for and get out. “You alright?” 

The shaking against him worries him at first until he realizes she’s _laughing_ , sliding a leg up over both of his to fit herself against his side, the soft swells of her breasts distracting even though he’s very much done. “Am I? I should ask you the same question.” 

In response, he gingerly rolls over onto his side, hyper-aware of the wet spot on the other side of the frankly absurdly sized bed, and presses a kiss to what he’s pretty sure is her cheek. Motor skills are still a bit of a struggle and leave a bit to be desired, but it has the intended effect, Allura folding herself into him with a pleased hum. “I’m great,” Shiro says with full honesty, humming when she tucks her head under his chin, her fingers trailing lightly up and down his back. “Thank you.” 

“Of course, Shiro.” It’s a little strange to feel the lack of tentacles right now, almost like he expects to feel them when he skims a hand down over her side, but despite how fun that _was_ , this is better. “Remind me to show you holos of Malnuans, later.” 

He tries to go through his memories to see if he’s ever encountered one before, but the name doesn’t sound familiar. Perhaps he met one in the Gladiator arenas, but it doesn’t seem likely. “Why Malnuans?” 

Allura shifts against him, pulling back enough to smile up at him, wicked and sharp. “They have six arms and are very...solidly built,” she says, clearly delighting in the way Shiro shivers in response, her hand petting along his back. “I will take that as as a yes, then.” 

It’s very much a yes.

**Author's Note:**

> Questions uttered during the writing and editing of this:  
> \- Can you use cock hungry in a fic where the focus is on tentacles?  
> \- Is Shiro slutty enough?  
> \- No but really is he as clearly into this as he needs to be? No, okay, make him way more into it.
> 
> Thanks to Brig for editing~~


End file.
